1. Field of the Invention
The present invention relates generally to computer-based athlete performance rating systems and methods. More particularly, the present invention relates to computer-based systems and methods of rating and ranking tennis players.
2. Description of the Prior Art
Over the past century, tennis players in the United States have been developed primarily through age- and gender-based events (such as tournaments), the results of which are used to determine their rankings. Primary goals of such events have been player development and expansion of the sport.
A great amount of time and resources have been put into the United States Tennis Association's (USTA's) National Tennis Rating Program (NTRP), a program that attempts to rate players according to their respective talent/skill levels, in order to promote competitive match play between players of similar tennis skill.
Under the NTRP and other prior rating schemes of this type, a player typically is initially assigned a rating based on a very subjective assessment of the player's tennis skills. This assessment is typically conducted by a local tennis professional, after having watched the player hit tennis balls for some period of time. Thereafter, whenever the player plays sanctioned matches against other players having the same rating, the results of those matches are recorded. If, after playing a number of matches against like-rated opponents, the player has established a record of badly beating nearly all his/her opponents, then the player will be bumped up to the next higher rating level. If, after playing a number of matches against like-rated opponents, the player has established a record of losing badly to nearly all of his/her opponents, then the player will be bumped down to the next lower rating level. Otherwise, the player's rating will remain the same.
A drawback of such prior rating schemes is that they do not encourage playing outside of one's own rating level, which is a well known path to improving one's game. Such prior rating schemes also are not suited for real-time adjustments in individual players' ratings, but, instead, are better suited for making incremental end-of-season rating adjustments.
While prior rating systems of this type have been in use for many years, they are primarily designed to address the levels of recreational players. Today, they are used largely to rate players in adult tennis leagues. Prior rating systems of this type do not provide a wide range of levels to easily distinguish one level from another across the wide spectrum of competitive play, which, in the NTRP, for example, has caused a glut of players rated from about 2.5-5.0.
Because, in prior rating schemes of this type, criteria for determining individual player ratings are highly subjective, rating levels assigned to similarly talented players vary widely from region to region. Such ratings, therefore, tend to be fairly meaningless outside of the sphere of recreational tennis leagues. And, because they inherently are focused on intra-rating-level play (rather than inter-rating-level play), it is well known that vast numbers of players commonly “game the system” to acquire lower-than-appropriate ratings in order to qualify for regional and national championship tournaments. Such widespread practice of “gaming the system” badly diminishes the effectiveness and accuracy of such prior rating systems.
As distinguished from “rating” schemes, various methods of “ranking” players are also known. As used herein, the term “rating” refers to a grouping level in which all players who are purported to be of a comparable skill level are said to have the same “rating”. As used herein, the term “ranking” distinguishes from the term “rating”, and refers to the respective hierarchical positions of individual players within one or more groups.
Virtually all prior ranking systems pertain to (i.e., only calculate rankings for) players within specific categories, such as age-based, education-based, geographically-based, or amateur/professional status-based categories. When players move from one category to another category, intra-category rankings invariably cannot be transferred or “carried over” to the new category. Thus, similar kinds of problems arise in the proper identification of a player's true level of skill when comparisons to players in other categories are attempted:                Juniors who move up to the next age category lose ranking points they have earned and have to begin all over again, often at great expense in time and money;        Potential college recruits cannot readily assess how they would compare to players on a given college varsity team;        High School players from one region cannot readily assess how they would compare to high school or college players in another geographic region;        Outside-of-category results (such as inter-sectional match results) do not count towards one's (sectional) ranking, thereby discouraging inter-sectional play;        Even so-called “blue chip” first year college players cannot qualify for national collegiate events based on their junior rankings, because college rankings and ratings are based on college match results, alone, and such players have difficulty quickly accruing enough ranking points to qualify for such events; and,        Players from different age groups are evaluated (i.e., ranked and rated) separately and differently, thereby inhibiting meaningful comparison of players who are in different age groups.        
Various prior methods for calculating a player's “ranking” are known. Many are largely subjective; others are somewhat less so. Those that rely on subjective criteria for assigning ranking positions are inherently flawed.
Among the more objective prior methods of determining a player's ranking, data such as overall win-loss record, strength of opposition, margin of victory/loss, or head-to-head match results are used to calculate rankings.
A problem with all such prior ranking systems that attempt to objectively rank players is that, aside from a consideration of the opponents' rankings, the same “weight” (i.e., importance in calculating a ranking) is given to each match-result data set, regardless of who the match opponents are. Thus, in prior objective ranking systems, the weight given to the match results for a match against a veteran match player would typically be the same as the weight given to the match results for a match against a newly-rated player—even though match results against newly-rated players (i.e., players whose own rating levels are of questionable accuracy) are inherently less reliable indicators of a player's skill level than are match results against players whose rating level have been repeatedly verified.
Another problem with all such prior ranking systems is that either (1) the same “weight” (i.e., importance in calculating a ranking) is given to each match-result data set regardless of the match format (e.g., two out-of-three sets, three-out-of-five sets, pro set, etc.), or (2) only those matches that are contested using the same match format are considered in calculating rankings. Thus, in all prior ranking systems, either a win in a best-three-out-of-five-sets match is counted the same as winning, say, a single pro set, or the results of one of those matches (typically, the shorter pro set match) would simply be ignored.
Generally speaking, prior systems that are used to calculate rankings are not suitable for calculating ratings; and, prior systems that are used to calculate ratings are generally not suitable for calculating rankings. This is primarily so in the former instance because prior systems that are principally used to determine player rankings (i.e., players' positions relative to each other) do not measure or process those attributes that are indicative of a player's general level of play (i.e., rating). And this is so in the latter instance because prior systems that are principally used to determine a player's general level of play (i.e., rating) are, at best, only able to calculate the relative positions (i.e., ranking) of like-rated players. In such prior rating systems, match-result data sets for matches contested between players who are at different rating levels are typically thrown out (i.e., disregarded). Thus, they are not useful for determining composite rankings of individual players who are at different rating levels.
Another problem associated with prior methods of rating/ranking players across a broad spectrum of playing levels relates to the disparate ways that amateurs and professional rankings are typically calculated. While the NTRP method depends on win-loss records in matches against like-rated players, the Association of Tennis Professionals (ATP), for example, ranks professional tennis players in accordance with how many “ranking points” a player accrues over a given time period (e.g., during the previous twelve month period), and the Intercollegiate Tennis Association (ITA) ranks collegiate players based on their “best wins”. It is inherently problematic to transfer player ratings or rankings from one such prior system to another as a player moves from one category to another, such as from amateur high school player to collegiate player to professional player to amateur senior player.
In prior ranking systems like the above-mentioned ATP system, the more ranking points a player accumulates, the higher the player's ranking. The number of “ranking points” awarded to a player depends on to which round (e.g., round of 32, round of 16, quarter-final, semi-final, final, champion) the player wins matches in sanctioned tournaments, with successive rounds being worth more points than earlier rounds, and with more important tournaments (such as Grand Slam tournaments) being worth more points than less important tournaments.
One problem with this prior method of calculating rankings relates to the fact that the rankings are not directly based on “whom” one beats (or loses to), but are, instead, based on “when” (i.e., in what round) and “where” (i.e., in what tournament) the win (or loss) occurs. This prior method of calculating rankings is further skewed because ranking points are accrued—meaning, for example, that between two players of comparable talent, one player (even the less talented of the two) can be more highly ranked than the other simply by virtue of playing in more tournaments. This prior method of ranking tennis players is generally skewed in favor of veteran players and against new players on the circuit. Thus, as will be appreciated by those skilled in the art, this prior system is not suitable for ranking, in a single list, a wide spectrum of players, ranging from amateur players, to new professional players, to seasoned veteran professionals.
Another well known method of ranking players is illustrated by the system used by the Intercollegiate Tennis Association (ITA). In prior ranking systems of this type, a player's ranking is based on his/her (half-dozen, or so) “best” wins. Thus a player that has wins against, say, seven opponents who are all ranked in the top 25 will be ranked higher than a player who only has only three wins against top-25 opponents and whose four next best wins are against opponents ranked, say, between 26 and 50—even if the second player is considerably better than the first player.
Although this type of prior ranking system does, in some instances, award the scheduling of play against highly ranked competition, it inherently penalizes (i.e., attributes a lower ranking to) very good players who, for one reason or another, do not have an opportunity to play against more highly ranked players. Accordingly, this prior ranking system is skewed in favor of players who play lots of matches and do so against highly ranked competition, and is skewed against (i.e., attributes a lower ranking to) new players and other players who have not played lots of matches against highly ranked competition.
Another problem with both the ATP and the ITA ranking schemes is that, in calculating a player's ranking, neither scheme considers the how badly, or how closely, a player beats his/her opponent; but, instead, only considers whether he/she won or lost the match. Thus, with all other things being equal, in such prior ranking systems a player who beats an opponent 6-0, 6-0 would be ranked the same as a player who beat that same opponent 7-5, 6-7, 7-5.
There is, then, a need for an objective universal tennis rating and ranking system that can be used to rate and rank all tennis players on a common scale.
Such a universal rating and ranking systems would advantageously encourage, for example, younger players to develop more quickly by competing regularly against older players.
Such a universal rating and ranking system would also advantageously expand the pool of potential local opponents (beyond one's own gender- and age-groups) for young players, thereby increasing local level-based competitions, reducing missed class-time (that would otherwise be spent travelling to play matches against like-rated players of the same age and gender), and reducing the pressure to resort to online schooling due to the considerable travel needed (under prior ranking systems) to compete nationally.
Such a universal rating and ranking system would also advantageously encourage elite adult players to stay in the game longer than is currently the practice
Such a universal rating and ranking system would also advantageously provide more “at risk” juniors (juniors who are not good enough to win a round in regular age-based competitions and are likely to give up) with more friendly entry-level tournament play.
Such a universal rating and ranking system would also advantageously make tennis more affordable, since it would make it easy for many more players—young and old—to find suitable competition locally, without the need for extensive travel.